Update README.md with JOSS badges

[odunbar]

Purpose

To-do

Content

• adds badge and link for JOSS
• moves files into JOSS subdirectory
• removes the GitHub action that builds the paper.pdf

---

• [ ] I have read and checked the items on the review checklist.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.27%. Comparing base (acf1051) to head (18d0760). Report is 15 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #308 +/- ## ========================================== + Coverage 88.17% 88.27% +0.09% ========================================== Files 8 8 Lines 1184 1185 +1 ========================================== + Hits 1044 1046 +2 + Misses 140 139 -1 ```

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